Synthesis and characterization of a new guar gum 4‐hydroxybenzoic acid resin and its use for the separation of heavy metal ions in industrial effluents

Hydroxybenzoic acid group has been incorporated onto guar gum by modified Porath's method of functionalization of polysaccharides. The newly synthesized guar gum 4‐hydroxybenzoic acid (GHBA) resin was characterized by Fourier‐transform infrared spectroscopy, elemental analysis, ion‐exchange capacity, column reusability, and physicochemical properties. The distribution coefficient (K_d) values and effect of pH on chelation of these metal ions using batch method were studied. The separations of mixture of Fe²⁺, Zn²⁺, Cu²⁺, Cd²⁺, and Pb²⁺ metal ions on GHBA resin on the basis of their distribution coefficient at various pH were also achieved using column chromatography. The effect of experimental parameters such as pH, treatment time, agitation speed, temperature, adsorbent dose, initial metal ion concentration, and flow rate on the removal of metal ions has been also studied. GHBA resin is effective adsorbents for the removal of different toxic metal ions from aqueous solutions and follows the order: Fe²⁺ > Zn²⁺ > Cu²⁺ > Cd²⁺ > Pb²⁺. POLYM. ENG. SCI. 2013. © 2012 Society of Plastics Engineers     

Selectivity and competitive mechanism of cation exchange resin for Fe,Mg, and Al ions in phosphoric acid

The presence of iron, magnesium, and aluminum elements as the primary impurities in wet-process phosphoric acid (WPA) adversely affects the industrial phosphoric acid and subsequent phosphorus chemical products. This study aims to investigate the selectivity and competition mechanism of Sinco-430 cation exchange resin for Fe, Mg, and Al ions in phosphoric acid solution. By studying the effects of different process conditions on the removal efficiency, the suitable conditions for the static removal of metal ions from Fe-Mg, Al-Mg, and Fe-Al binary systems were determined: solid–liquid mass ratio (S/L) of 0.3, phosphoric acid concentration of 27.61 wt.%, system temperature of 50°C, and rotational speeds of 200, 400, and 200 rpm, respectively. By calculating the selectivity coefficients of the resin for metal ions under different experimental conditions and mutual replacement experiments, the semi-empirical formulas for the selectivity coefficients were derived and order of selectivity was determined as follows: Mg²⁺ > Fe²⁺ > Al³⁺. Visual MINTEQ 3.1 software and density functional theory (DFT) calculations demonstrated that at low pH, the main forms of Fe, Mg, and Al present in phosphoric acid were FeH₂PO₄⁺, Mg²⁺, and AlH₂PO₄²⁺, respectively. This finding explained the differences in selectivity of the resin for Fe, Mg, and Al. The dynamic removal of metal ions from phosphoric acid was investigated. The order of metal ion selectivity of the resin by the dynamic method is the same as that of the static method, and the dynamic exchange behaviour was most consistent with the Yan model.     

ION EXCHANGE BEHAVIOUR OF CHELATING RESIN DOWEX A-1WITH ACTINIDES AND LANTHANIDES

Adsorption studies of several actinides and lanthanides have been carried out by chelating ion exchange resin Dowex A-1. The metal ions studied were Pu⁴⁺, Zr⁴⁺, UO₂ ⁺⁺, Am³⁺, Cm³⁺, Bk³⁺, Cf³⁺, Eu³⁺, and Tm³⁺. The separation factors between consecutive trivalent actinides and between Am(III) and Eu(III) have been evaluated. Mechanism of adsorption of actinides and lanthanides from different aqueous media has been discussed. An ion exchange procedure for the separation of Pu⁴⁺ and UO₂ ⁺⁺ has been developed using this resin.     

Synthesis of resin IV: Salicylic acid,diaminonaphthalein, and formaldehyde terpolymer and its ion exchange

This article reports the synthesis, characterization, and ion exchange properties of a terpolymer. The terpolymer resin salicylic acid‐diaminonaphthalein‐formaldehyde (SDNF) was synthesized by the condensation of salicylic acid and diaminonaphthalein with formaldehyde in the presence of a hydrochloric acid catalyst. Terpolymer resin was characterized by elemental analysis, infrared (IR) spectroscopy, nuclear magnetic resonance spectroscopy, and UV–Visible spectral studies. The number average molecular weight of the resin was determined by nonaqueous conductometric titration. Chelation ion exchange properties have also been studied for Fe³⁺, Cu²⁺, Ni²⁺, Co²⁺, Zn²⁺, Cd²⁺, Pb²⁺ ions employing a batch equilibrium method. It was employed to study the selectivity of metal ion uptake involving the measurements of distribution of a given metal ion between the polymer sample and a solution containing the metal ion. The study was carried out over wide pH range and in a media of various ionic strengths. The terpolymer showed higher selectivity for Fe³⁺, Cu²⁺, and Ni²⁺ions than for Co²⁺, Zn²⁺, Cd²⁺, and Pb²⁺ ions. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010     

Sorption properties of the iminodiacetate ion exchange resin,amberlite IRC‐718, toward divalent metal ions

The sorption properties of the commercially available cationic exchange resin, Amberlite IRC‐718, that has the iminodiacetic acid functionality, toward the divalent metal‐ions, Fe²⁺, Cu²⁺, Zn²⁺, and Ni²⁺ were investigated by a batch equilibration technique at 25°C as a function of contact time, metal ion concentration, mass of resin used, and pH. Results of the study revealed that the resin exhibited higher capacities and a more pronounced adsorption toward Fe²⁺ and that the metal‐ion uptake follows the order: Fe²⁺ > Cu²⁺> Zn²⁺ >Ni²⁺. The adsorption and binding capacity of the resin toward the various metal ions investigated are discussed. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2008     

Interaction of heavy metal ions with an ion exchange resin obtained from a natural polyelectrolyte

An ion exchange resin was synthesized by using a natural polyelectrolyte, sodium alginate, and barium ion as a cross-linker reagent. Resin was characterized by TGA and SEM. Equilibrium and kinetic experiments of Pb²⁺, Hg²⁺, Ni²⁺, Co²⁺, Fe²⁺, and Fe³⁺ ions uptake by barium alginate beads were carried out in batch-type experiments under different values of pH. The removal efficiency increases with increasing pH. The uptake of metal ions occurs rapidly in the first hour. Maximum retention capacity was also determined being Fe(II) > Fe(III) > Co(II) > Ni(II) > Pb(II) > Hg(II) in mmol/g dry beads basis. Elution from the loaded resins at maximum capacity was studied by using HCl and HNO₃ as eluents at different concentrations.     

Conversion of soybean oil into ion exchange resins: Removal of copper (II), nickel (II), and cobalt (II) ions from dilute aqueous solution using carboxylate‐containing resin

An ion‐exchange resin containing carboxylic acid groups was prepared by reaction of epoxidized soybean oil with triethylene tetramine, followed by hydrolysis of glycerides by using sodium hydroxide solution. The cation exchange capacity of the resins was determined to be 3.50 mequiv/g. The adsorption capacity for Cu²⁺, Ni²⁺, and Co²⁺ on the obtained resin at pH 5.0 was found to be 192, 96, and 78 mg/g, respectively. Effect of pH on the adsorption capacity for copper (II), nickel (II), and cobalt (II) ions were also studied. Cu²⁺, Ni²⁺, and Co²⁺ were adsorbed at a pH above 3. These metal ions adsorbed on the resin are easily eluted by using 1N HCl solution. The selectivity of the resin for Cu²⁺ from mixtures containing Cu²⁺/Co²⁺/Ni²⁺ ions in the presence of sodium chloride was also investigated © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 84: 2386–2396, 2002     

Chelation ion‐exchange study of copolymer resin derived from 8‐hydroxyquinoline 5‐sulphonic acid,oxamide, and formaldehyde

Copolymers (8‐HQ5‐SAOF) were synthesized by the condensation of 8‐hydroxyquinoline 5‐sulphonic acid (8‐HQ5‐SA) and oxamide (O) with formaldehyde (F) in the presence of acid catalyst. Four different copolymers were synthesized by using varied molar proportion of the reacting monomers. Copolymer resin composition has been determined on the basis of their elemental analysis and average molecular weights of these resins were determined by conductometric titration in nonaqueous medium. Viscometric measurement in dimethyl sulphoxide (DMSO) has been carried out with a view to ascertain the characteristic functions and constants. Electronic spectra, FTIR, and proton nuclear magnetic resonance spectra were studied to elucidate the structures. The newly synthesized copolymer proved to be a selective chelating ion‐exchange copolymer for certain metals. The chelating ion‐exchange properties of this synthesized copolymer was studied for different metal ions such as Fe³⁺, Cu²⁺, Ni²⁺, Co²⁺, Zn²⁺, Cd²⁺, and Pb²⁺. A batch equilibrium method was used in the study of the selectivity of metal ion uptake involving the measurements of the distribution of a given metal ion between the copolymer sample and a solution containing the metal ion only for representative copolymer 8‐HQ5‐SAOF‐I due to economy of space. The study was carried out over a wide pH range, shaking time, and in media of various ionic strengths. The copolymer showed a higher selectivity for Fe³⁺, Cu²⁺, and Ni²⁺ ions than for Co²⁺, Zn²⁺, Cd²⁺, and Pb²⁺ ions. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010     

Application of a Novel Hybrid Cation Exchange Material in Metal Ion Separations

A novel hybrid cation exchange material of the class of tetravalent metal acid (TMA) salt, titanium diethylene triamine pentamethylene phosphonate (TiDETPMP) has been synthesized by the sol gel method. The material has been analyzed by spectroscopy and thermal methods. Physico-chemical and ion exchange characteristics have also been studied. The distribution coefficient (K _d ) has been determined in aqueous as well as various electrolyte media/concentrations for Co²⁺, Ni²⁺, Cu²⁺, Zn²⁺ (transition metal ions) and Cd²⁺, Hg²⁺, Pb²⁺, Bi³⁺ (heavy metal ions) using TiDETPMP. Based on the differential affinity/selectivity, the breakthrough capacity (BTC) and elution behavior of various metal ions towards TiDETPMP, a few binary and ternary metal ions separations have been carried out.     

Synthesis and study of the chelating properties of 3-carboxy-4-hydroxyacetophenone-formaldehyde resins

3-Carboxy-4-hydroxyacetophenone (CHAP) was polycondensed with various proportions of formaldehyde using alcoholic alkali as catalyst. The resin samples, designated as CHAP-F, have been characterized by elemental analyses and IR spectroscopy, by estimation of their number average molecular weights (M?_n), by measurement of intrinsic viscosity, and by TGA. Polymeric metal chelates of one CHAP-F sample with Cu²⁺, Fe³⁺, Co²⁺, Ni²⁺, and UO₂²⁺ ions have been prepared and characterized. Ion-exchanging properties of one CHAP-F resin sample for Fe³⁺, Cu²⁺, and Ni²⁺ metal ions are studied by the application of the batch-equilibration method.     

Synthesis,Ion Exchange Properties,and Applications of Amorphous Cerium(III) Tungstosilicate

Abstract

A novel hetropolyacid-based cation exchanger cerium(III) tungstosilicate was synthesized in amorphous form by mixing tungstosilisic acid (TSA) solutions to cerium(III) nitrate solutions at different Ce:TSA ratios. The materials were precipitated from the liquid phase by raising the pH of the solutions using sodium hydroxide. The produced ion exchange powders were characterized using powder X-ray diffractometry, thermogravimetry, infrared spectrometry, inductively coupled plasma and atomic absorption elemental analysis. The materials which were dried at 50°C were found to be stable in water, dilute acids, alkaline solutions, and high temperature up to 1000°C. The Ion exchange properties of the synthesized samples were studied by measuring the distribution coefficients (K_d) for 29 metal ions in demineralized water and nitric acid media. On the basis of K_d values, some quantitative separations such as Co²⁺-Pb²⁺, Cr³⁺-Zr⁴⁺, and Mo⁶⁺- W⁶⁺ are achieved on their columns.     

SPOTLIGHT ON MANUFACTURING TRENDS IN JAPAN

Three reactive and functional polymers were synthesized by reacting formaldehyde with the phenolic Schiff bases derived from 4,4′-diaminodiphenylsulfone and o-, m-, and p-hydroxybenzaldehydes, respectively. The metal ion uptake behavior of these resins towards Cu²⁺, Ni²⁺, Co²⁺, and UO₂ ²⁺ ions in dilute aqueous media was studied. The optimum conditions for the absorption of metal ions were determined by varying the various parameters like contact time, size of the sorbents, concentration of the metal ion solutions, and the pH of the reaction medium. Suitable conditions were ascertained for preferential adsorption of the above metal ions from the salt solutions containing other interfering ions such as Na⁺, K⁺, and Mg²⁺. Presence of these alkali and alkaline earth metal ions in the salt solutions did not affect the adsorption behavior of the resins. It was observed that the structural features of the resins have a profound effect on the uptake characteristics. The position of the OH group present in the meta position with respect to the imine nitrogen atom in the resin, demonstrated a significant influence on the extent of metal ion adsorption by the resin. Out of the three resins reported here, the resin derived from the Schiff base of m-hydroxybenzaldehyde-4,4′-diaminodiphenylsulfone showed higher efficiency in uptake of metal ions from the solutions than the corresponding resins derived from the Schiff bases of o- and p-hydroxybenzaldehyde-4,4′-diaminodiphenylsulfone.     

Kinetics and Equilibrium Studies for the Removal of Cobalt,Manganese, and Silver in Ethanol using Dowex 50W-x8 Cation Exchange Resin

Organic solvents such as ethanol, find a wide range of applications in fuel, pharmaceutical industries, food industries, and paint formulations, among others. The removal of Ag(I), Co(II), and Mn(II) ions in ethanol by cation exchange resin, Dowex 50W-x8, was investigated. The adsorption characteristics of metal ions onto Dowex 50W-x8 resin were described by Langmuir isotherms. The maximum sorption exchange capacities at 298 K were obtained as 47.4 mg g^?1, 52.6 mg g^?1, and 58.5 mg g^?1 for Ag(I), Co(II), and Mn(II), respectively. The data was also fitted to Temkin and Dubinin-Radushkevich adsorption isotherm models to evaluate other adsorption properties. The ion exchange of silver, cobalt, and manganese on cation exchange resin followed pseudo-second-order kinetics, and the intraparticle diffusion was rate-determining step. The thermodynamic parameters indicated that the sorption of metal ions onto Dowex 50W-x8 resin was spontaneous (negative ΔG°) and endothermic in nature (positive ΔH°) implying that the adsorption capacity increased with increasing temperature. The resin can be regenerated by eluting metal ions with 3.0 mol L^?1 HNO₃ followed by washing it with 10 mL of Millipore water and 10 mL of 2.0 M NaOH, respectively. The proposed method was applied for metal ion removal in real ethanol samples.     

Studies of Retention and Reusable Capacities of Melamine Formaldehyde Based Terpolymer Against Some Toxic Metal Ions by Batch Equilibrium Method

Chelating terpolymer resin was synthesized and characterized by elemental, physico-chemical, spectral, SEM, XRD, and GPC to elucidate the structure and properties of the terpolymer. Ion-exchange analysis involving evaluation of metal ion uptake in different electrolyte concentrations, pH, and time have been studied to assess the retention capacities of the terpolymer for the metal ions viz. Fe³⁺, Co²⁺, Ni²⁺, Cu²⁺, Zn²⁺, and Pb²⁺. The adsorption isotherm was evaluated using the Langmuir and Freundlich isotherms models and the results were found best fitting with each other. The resin can be successfully used in the field of recovery of metal ions from effluents and contaminated water.     

Synthesis and adsorption properties,toward some heavy metal ions,of a new polystyrene‐based terpyridine polymer

A novel polymeric ligand having 2,2′:6′,2″‐terpyridine as pendant group was prepared through a Williamson type etherification approach for the reaction between 4′‐hydroxy‐2,2′: 6′,2″‐terpyridine and the commercially available 4‐chloromethyl polystyrene. The chelating properties of the new polymer toward the divalent metal ions (Cu²⁺, Zn²⁺, Ni²⁺, and Pb²⁺) in aqueous solutions was studied by a batch equilibration technique as a function of contact time, pH, mass of resin, and concentration of metal ions. The amount of metal‐ion uptake of the polymer was determined by using atomic absorption spectrometry. Results of the study revealed that the resin exhibited higher capacities and a more pronounced adsorption toward Pb²⁺ and that the metal‐ion uptake follows the order: Pb²⁺ > Cu²⁺ > Zn²⁺ > Ni²⁺. The adsorption and binding capacity of the resin toward the various metal ions investigated are discussed. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012     

Equilibrium data of the exchange of Cu2+, Cd2+ and Zn2+ ions for H+ on the cationic exchanger Lewatit TP‐207

Equilibrium ion exchange isotherms in aqueous medium of H⁺/Cu²⁺, H⁺/Zn²⁺ and H⁺/Cd²⁺ on a weak acid resin Lewatit TP‐207, at different pH values and at 298 K have been determined in order to assess the possibility of using ion exchange to eliminate heavy metal ions from industrial aqueous liquid streams. The experimental equilibrium data have been satisfactorily correlated using a Langmuir‐type empirical equation. It was found that the operating resin capacity with respect to each metal ion increased with increase in solution pH, in accordance with a second‐degree polynomial equation. Taking into account the variation of operating capacity with pH, each system exhibited a unique separation factor, namely all the experimental points can be described by a unique isotherm in a dimensionless form. Resin Lewatit TP‐207 exhibited the following selectivity order: Cu²⁺ > Zn²⁺ > Cd²⁺ at 298 K. Copyright © 2004 Society of Chemical Industry     

Synthesis of a novolac‐based 3‐aminopropylsiloxane resin and its application for the removal of Cu2+, Cr3+, and Ni2+ from electroplating wastewater

Novolac resin was modified with 3‐aminopropyltrimthoxysilane to obtain phenol‐formaldehyde‐aminopropylsiloxane resin (PF‐APS). Fourier transformation infra‐red spectra, thermogravimetric analysis, elemental analysis, and pH‐metric titration were used to characterize PF‐APS. Its chemical formula was suggested to be C₁₄H_12.49N_0.1O₂Si_0.1. The resin shows high experimental metal ions uptake capacity within short time of equilibration. The metal capacity was determined by atomic absorption spectrometry to be 0.787 mEq Cu/g. Maximum separation efficiencies of Cu²⁺, Cr³⁺, and Ni²⁺ from aqueous solutions on PF‐APS were at pH 8.0 and time of stirring 60 min; 94.0%, 90.8%, 83.2%, respectively. No significant interference from the background ions Na⁺, Cl^?, and was observed on the separation process. The heavy metal ions were eluted using 0.01 mol L^?1 EDTA at 65°C releasing >94% of the separated metal ions. The method of separation was applied successfully to remove the heavy metal ions Cu²⁺, Cr³⁺, and Ni²⁺ from electroplating wastewater from Dekirnis, Dakahlia Governorate, Egypt. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131, 40993.     

Chelation ion‐exchange properties of copolymer resin derived from 4‐hydroxyacetophenone,oxamide, and formaldehyde

A copolymer (4‐HAOF) prepared by condensation of 4‐hydroxyacetophenone and oxamide with formaldehyde in the presence of an acid catalyst proved to be a selective chelating ion‐exchange copolymer for certain metals. Chelating ion‐exchange properties of this copolymer were studied for Fe³⁺, Cu²⁺, Ni²⁺, Co²⁺, Zn²⁺, Cd²⁺, Pb²⁺, and Hg²⁺ ions. A batch equilibrium method was employed in the study of the selectivity of metal‐ion uptake involving the measurements of the distribution of a given metal ion between the copolymer sample and a solution containing the metal ion. The study was carried out over a wide pH range and in media of various ionic strengths. The copolymer showed a higher selectivity for Fe³⁺ ions than for Co²⁺, Zn²⁺, Cd²⁺, Pb²⁺, Cu²⁺, Ni²⁺, and Hg²⁺ ions. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 89: 787–790, 2003     

Amidoximation of Cyano Group for Chelating Ion Exchange of Some Heavy Metal Ions from Wastewater

Ion exchange behavior of some heavy metal ions, Pb²⁺, Ni²⁺, and Cd²⁺, onto amidoximated polyacrylonitrile based Ce(IV) phosphate was investigated. Polyacrylonitrile based Ce(IV) phosphate was prepared and followed by functionalization of the cyano group to amidoxime group with hydroxylamine. The amidoximated resin was characterized using FT-IR and SEM. Removal of Pb²⁺, Ni²⁺, and Cd²⁺ ions from aqueous solution was examined by studying some factors using the batch technique such as effect of pH, contact time, initial metal ion concentration, and temperature. Some kinetic and isotherm models had been applied. The calculated amount of the sorbed values in case of the pseudo-second-order model are closer to the experimental data than that of the pseudo-first-order model, and with a correlation coefficients R² > 0.99. Therefore, the sorption of the three metal ions can be approximated more favorably by the pseudo-second-order model. The sorption process obeys the Freundlich isotherm model. The sorption has an endothermic nature which is indicated by the positive value of the enthalpy change, ΔH, the high positive values of the entropy change, and ΔS show the increased randomness at the solid/solution interface. The obtained negative values of free energy change, ΔG, indicate the feasibility and the spontaneous nature of the sorption process.     

Removal of toxic metal ions by using composite cation-exchange material

Polyanilinezirconium(IV) arsenate composite cation exchange material was synthesized under different experimental conditions by the incorporation of polyaniline into the matrices of inorganic precipitate (zirconium(IV)arsenate). The experimental parameters such as concentration, mixing volume ratio, and pH were established for the synthesis of the material. Ion-exchange material that was synthesized at pH 1.0 showed an ion exchange capacity of 1.33 meq g⁻¹ for Na⁺ ions. The composite material exhibits improved ion-exchange capacity along with chemical and thermal stability. The exchanger was characterized based on FTIR, TGA, XRD, and SEM analysis. The X-ray diffraction study shows semi-crystalline nature of the material. The distribution coefficient studies (K_d) of metal ions on the material were performed in diverse solvent systems. Based on K_d values the material was found to be selective for Pb(II) and Hg(II) ions. Some analytically important binary separations of metal ions in synthetic mixtures viz. Ba²⁺-Pb²⁺, Pb²⁺-Ni²⁺, Cd²⁺-Hg²⁺, Ni²⁺-Hg²⁺, Zn²⁺-Pb²⁺, Ca²⁺-Bi³⁺, Al³⁺-Hg²⁺, and Ca²⁺-Pb²⁺ were achieved on the columns of polyanilinezirconium(IV) arsenate cation exchanger. © 2012 Wiley Periodicals, Inc. J Appl Polym Sci, 2012